DESPITE BEING DESIGNED FOR KEYBOARDS, THE Leslie rotary speaker has played a major role in creating some of the most memorable guitar sounds around. Listen to Eric Clapton on “While My Guitar Gently Weeps,” Stevie Ray Vaughan on “Cold Shot,” or Hendrix on “Little Wing,”—they all used a Leslie to create those swirling tones. The new G37 is the first Leslie to be designed specifically for guitar. As with the keyboard version, it contains a pair of motor-driven rotors: one at the top of the cabinet that uses a compression driver and special double horn, and a larger one on the bottom that takes the sound from a stationary 12" speaker and disperses it though a rotating cylinder with an opening on one side. The “chorusing” effect created when sounds are whirled around a room is lusher and more 3-D than any static system can deliver—the only real downside is the machinery that’s required to generate a real Doppler sound effect. The G37 doesn’t solve that problem entirely. Yes it’s more compact than the big wooden Leslies of yore, but at just over 100 lbs, its still a serious thing to carry and it has no casters.
Inside the G37 is a 100-watt solid-state power amp that’s fed by a tube preamp. The two channels share a set of Bass, Mid, and Treble controls. Additionally the Clean channel has a Volume control, while the Overdrive channel sports Gain, Volume, and Contour controls. You can change channels with a panel-mounted switch or via an optional footswitch. The included two-button footswitch starts or stops the rotors and toggles between two different speeds that you preset with the low/high speed controls. If you get the optional V20RT speed pedal, you can vary the speeds infinitely—something that hasn’t been possible on other Leslie speakers. Also worth noting is that you can’t connect the G37 to an external amplifier. (If you want to be able to do that you’ll need the G27 model, which is the same as the G37 but without an internal amp.)
Plugging into the G37 with different singlecoil and humbucker guitars yielded some spectacular rotary effects. The dimensional sense is really something to behold— particularly if you’re used to hearing rotary simulators—and the way those textures change as the rotors speed up and slow down is so cool that it’s easy to get into pressing the Speed switch again and again to keep the effect going. Another cool thing about the G37 is how quiet its motors are. This is something you’ll most appreciate when recording, but it’s nice not to hear any significant mechanical noise other than the quiet whirring of the rotors as they spin.
The G37’s Overdrive channel offers a range of distortion sounds when you crank up the Gain control, but these tones have a rather strident quality that’s reminiscent of solid-state amp distortion. Using lower Gain settings helps to keep these artifacts to a minimum, but if you’re serious about having some grind in your swirl, consider using a distortion pedal in front of the G37. The Clean channel is very pure sounding and it adds no coloration to the rotary sounds other than what you dial in with the 3-band EQ.
In order to optimize the G37’s utility as a guitar amp, the speakers come to a halt facing forward when you switch off the rotary effect. Although this pumps out the sound in the right direction, the signal is still being fed though a downward firing 12 and a highfrequency horn. Could you use the G37 by itself to handle both straight and rotary sounds? Probably. However, the ideal situation would be to use the G37 along with a regular amp, and then route your guitar signal though an A/B/Y box so that you could switch between amp and Leslie, or use both together for an even wider sound. It’s a lot of gear to carry and set up, but if you’re serious about your swirl, adding the G37 to your rig is one of the best ways to go if you seek the ultimate rotary speaker experience.